1. Field of the Invention
The present invention relates to a mobile device, and particularly, to a switch unit for sensing a switched state of switch contact points by rotation, and a method for sensing a button-pressed state using the same.
2. Description of the Related Art
Recently, terminals having various performances have been available due to dramatic development in radio communications technologies. As a result, users have access to various multimedia services, additional functions and wireless Internet by using the high-functional mobile communications terminals.
FIG. 1 is a perspective view showing a mobile communications terminal according to a related art.
As shown, the mobile communication terminal of the related art includes a keypad unit 20 having various menu keys, functional keys, and number keys formed on a surface of a mobile communications terminal and two push switches 21a and 21b formed at one side surface thereof. The respective two push switches 21a and 21b, as shown in FIG. 2, are connected to a GPIO (General Purpose Input Output) port of an inner CPU (Central Processing Unit).
When a folder of the terminal is opened, a user operates the keypad unit 20 and the two push switches 21a and 21b to access various services, additional functions, wireless Internet, and the like. When the folder is closed, the user operates the two push switches 21a and 21b to work a camera, a backlight, and the like. For instance, the push switch 21a could be used for moving a menu selecting cursor up and the push switch 21b could be used for moving the cursor down. The push switches 21a and 21b could also be used for working the camera to take photographic images or to turn on the backlight by pressing it for a certain amount of time.
When the user presses the push switches 21a and 21b, as shown in FIG. 2, the switch contact points connect to each other. The CPU periodically measures a logical state of the GPIO port connected to the switch contact points to thereby recognize the switching operation.
However, in the related art mobile communications terminal, the CPU can not recognize whether the external push switches are purposefully pressed by the user or accidentally pressed, for example when the terminal is in a pocket or a bag. As a result, when the external push switch is pressed regardless of the user's intention, the CPU operates the camera, the backlight, or other such items corresponding to the pressed push switch. As a result, unnecessary consumption of a battery power occurs by performing unintended functions.